Abstract Details
Abstracts
Author: Omar E Lopez
Requested Type: Poster
Submitted: 2025-03-17 14:24:49
Co-authors: D. Vargun, C. D. Hauck, M. T. Beidler
Contact Info:
Oak Ridge National Laboratory
Oak Ridge National Laboratory
Oak Ridge, TN 37831
USA
Abstract Text:
A new procedure couples the Kinetic Orbit Runaway electrons Code (KORC) with the NIMROD extended-MHD code to simulate runaway electrons (REs) in the post-disruption plateau. KORC employs a barycentric search algorithm to integrate guiding-center orbits, delivering robust initial guesses for the Newton-Raphson logical-to-physical coordinate solver and ensuring reliable particle-to-mesh mapping in NIMROD, whose fields remain fixed here. Samples conform to experimentally observed parallel current profiles of RE beams during the plateau phase. Deposition in NIMROD is verified via a Python-based finite-element code that enforces poloidal periodicity and continuity at the magnetic axis. Accurate representation of near-axis fields necessitates finer mesh resolution to avoid under- or overshoots in current density due to orbit errors; however, refined meshes lead to increased statistical noise at a fixed particle count. An orbit-averaging approach accumulates partial current deposits over multiple kinetic steps, suppressing statistical noise at minimal extra computational cost. Incorporating KORC's kinetic routines directly into NIMROD establishes the groundwork for future self-consistent KORC-NIMROD simulations. This work is supported by the US DOE under contract DE-AC05-00OR22725
Characterization: 4.0
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